JP3851590B2 - Preceding ground mountain consolidation method using self-drilling bolt and FRP bolt - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for consolidating preceding ground using self-drilling bolts and FRP hollow bolts, and more specifically, an injection type fore-polling, which is frequently used as an auxiliary construction method for the purpose of improving preceding ground in tunnel excavation work. It relates to the drive coupler used for
[0002]
[Prior art]
6 and 7 show the state of implementation of conventional injection type forepoling.
[0003]
The conventional injection type fore-polling is, for example, in Section 237 of the “Tunnel Standard Specification (Mountain Construction Method)” and “Explanation” issued by the Japan Society of Civil Engineers, 1996, third edition. Bolts and pipes of the length of the same length, and at the same time, quick-setting cement milk and chemicals are injected under pressure to increase the stability of the top end. There is a self-drilling type that uses the same bolt, etc. "and it is introduced as" Reliable and has many achievements ".
[0004]
In actual application, as shown in Fig. 6, in the excavation of tunnels and underground cavities, the height of the ground is particularly low, for example, in highly weathered rocks and soft grounds, and in constructions with small soil cover thickness. For example, a pre-excavation is performed, and for example, a steel support 1 (for example, H120 × 120) arranged at intervals of about 1 m is shifted by one shift within a range of about 120 degrees in the elevation angle of the top as shown in FIG. A hollow steel pipe 2 having a length of about 35 mm and a length of about 3 to 4 m is cast at a predetermined interval at an elevation angle of about 25 to 35 ° from the tunneling direction to the front, so that cement, resin, etc. are solidified from the hollow steel pipe 2. The method of excavating the next 1m after filling the material and improving the ground at the front top is taken.
[0005]
[Problems to be solved by the invention]
By the way, in the conventional injection type fore-polling carried out in a soil with poor soil quality, as described above, it is necessary to insert a hole and a hollow steel pipe 2 for each steel support 1 and to perform the tunneling work. Is a cycle work that repeats a limited number of work types, and the work types are changed very frequently, and therefore the cycle time that affects the economic effect is prolonged.
[0006]
Therefore, the present invention provides a method for consolidating a preceding ground using a self-drilling bolt and an FRP hollow bolt that can shorten the cycle time as much as possible, pursue economic efficiency, and save labor for complicated work. It is an object to provide a drive coupler to be used.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention performs a pre-drilling with a self-drilling bolt having a hollow structure with a lost bit at the tip and having a continuous screw on the outer periphery, and then a FRP hollow bolt is subsequently placed. This drive is connected directly with the drive sleeve attached to the tip of the driving rod so that the FRP hollow bolt is installed in the inner hole of the long driving rod attached to the rock drill. Rotate and strike the coupler to drill the subsequent FRP hollow bolt to the ground, then, after pulling out the driving rod and drive sleeve, caulk the outlet from the ground of the FRP hollow bolt, A configuration in which a solidifying material is injected from the end of the subsequent FRP hollow bolt, discharged from the lost bit hole at the tip, and press-fitted into the ground is adopted.
[0008]
While implementing the above-mentioned ground solidification method in the direction of tunnel excavation, the excavation of the tunnel is advanced while excising the subsequent FRP hollow bolt part while carrying out every two or three of the steel supporters of the same shape Can be.
[0009]
The drive coupler is formed so as to couple the self-drilling bolt and the FRP hollow bolt, and a striking surface capable of transmitting striking and rotation directly from the drive sleeve provided at the tip of the driving rod on the outer surface of the drive coupler. When the plurality of spline protrusions and the subsequent FRP hollow bolts are driven, the protrusions do not collide with the previously excavated hole wall to make subsequent drilling difficult, and the excavated waste soil In order to prevent the passage from being hindered, a plurality of rounds with a slightly smaller diameter than the front lost bit are made so that the subsequent drilling operation can proceed while re-reaming the hole wall of the already-cut hole in front of the striking surface and the spline protrusion. A structure in which trimming edges independent in the direction can be provided.
[0010]
In this invention, in the implementation of injection-type fore-polling, first, a self-drilling bolt having a diameter somewhat larger than the diameter of the drilling hole in the fore-polling work or a lock bolt used in normal tunnel construction is attached to the self-drilling bolt, Pre-drilling is performed with this self-drilling bolt, and after the completion of the self-drilling bolt, a hollow bolt made of fiber reinforced plastic (FRP) is connected to the rear end of the self-drilled bolt with a specially shaped drive coupler. However, if the FRP hollow bolt is directly struck, the FRP hollow bolt may be destroyed depending on the natural ground and the drilling operation cannot be performed. Therefore, according to the means of the present invention, the driving rod of the rock drilling machine is more than the FRP hollow bolt. Is also made of a long and large diameter, and is driven in by placing an FRP hollow bolt inside the long driving rod. Direct head drive sleeve fixed to the tip of, those taking means for implementing the drilling drive coupler is striking and rotation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows an embodiment of injectable forepoling according to the present invention.
[0013]
In the embodiment of FIG. 1, first, the lost bit 12 having a diameter somewhat larger than the drilling bit having a diameter of 40 to 50 mm used in the conventional method, for example, 65 mm in diameter and having the solidified material discharge port 11 is hollow. The structure is provided with a continuous rolling screw on the outer peripheral surface, and is fixed to the tip of a self-drilling bolt 13 having a diameter of 28.5 mm and a length of 4 m. Place in the ground in the same way as rock bolt drilling so that the elevation angle is °.
[0014]
Next, a 2.5 m FRP hollow bolt 14 made of fiber reinforced plastic (FRP) having a connection screw structure at least at the end is attached to the rear end of the self-piercing bolt 13 that has been previously placed, and a specially shaped drive coupler. 15 to connect.
[0015]
At the same time, a rock drill 18 mounted on a guide cell 17 provided in a tunnel jumbo 16 or the like has a driving sleeve 19 and a hollow driving rod having a length of about 3 m which is slightly longer than the FRP hollow bolt 14. 20, the driving rod 20 and the drive sleeve 21 are inserted so as to contain the FRP hollow bolt 14, and the drive sleeve 21 screwed and fixed to the tip of the driving rod 20 is externally fitted to the drive coupler 15.
[0016]
The rotation of the rock drill 18 is transmitted to the self-drilling bolt 13 via the drive sleeve 21 fixed to the driving rod 20 and the drive coupler 15, and the hitting is performed by hitting the drive coupler 15 with the drive sleeve 21. It is transmitted to the perforated bolt 13.
[0017]
Therefore, the rotation and hitting of the rock drill 18 are not directly transmitted to the FRP hollow bolt 14, but are directly transmitted to the specially shaped drive coupler 15, and further, the lost bit at the tip is passed through the self-drilling bolt 13 that has been placed in advance. 12 is transmitted.
[0018]
In this way, the drilling is advanced so as to pull the FRP hollow bolt 14 connected to the rear end of the self-drilling bolt 13, and the ground of the FRP hollow bolt 14 is formed by placing about 2 to 2.3 m. Is completed, the rock drill 18 on the guide cell 17 is retracted together with the driving sleeve 19, the driving rod 20 and the drive sleeve 21, so that the front drilling bolt 13 is 4 m in front and the drive coupler 15 is in the rear. A long hollow tube having a total length of about 6.5 m is formed by the FRP hollow bolts 14 having a length of about 2.5 m connected to each other.
[0019]
After that, the ground exit portion of the end of the FRP hollow bolt 14 is sealed with a caulking material 32 as shown in FIG. 2, for example, and then an injection jig is attached to the short self-piercing bolt 23 provided at the outlet end portion of the FRP hollow bolt 14. Fill and press the solidified material to complete the injection-type fore-polling work.
[0020]
After that, while excavating the FRP hollow bolt 14 with an excavator, the tunnel excavation was advanced by about 1 m, and the steel support 1 was stood at a distance of about 1 m from the previous support. An additional 1m is dug up and the support work is set up. The injection fore-polling work in which the FRP hollow bolt 14 connected by the self-drilling bolt 13 and the specially shaped drive coupler 15 is placed and the solidified material is press-fitted by the above procedure. Are carried out every other group.
[0021]
After that, tunnel excavation will proceed while repeating such cycle work.
[0022]
FIG. 3 shows a specific example of the self-drilling bolt 13 and the FRP hollow bolt 14 as a subsequent pipe. In this embodiment, short self-drilling bolts 22 and 23 are fixed and connected to both ends of the long FRP hollow pipe. A screw is provided, and a short self-piercing bolt 22 at the tip is screwed to the drive coupler 15. Note that the screw structure at the end may not be in this form, but may be a method in which, for example, a connection screw is directly formed on the surface of the FRP hollow bolt 14.
[0023]
FIG. 4 shows the shape of a drive sleeve constituting the present invention, and FIG. 5 shows the shape of a specially shaped drive coupler.
[0024]
The striking and rotation transmitted from the rock drill 18 through the driving sleeve 19, the long driving rod 20, and the drive sleeve 21, the striking surface 24 ′ at the tip of the drive sleeve 21 and the striking surface of the drive coupler 15. 24, the rotation is transmitted to the front self-drilling bolt 13 by a plurality of spline protrusions 25, and the drilling is advanced by the lost bit 12 at the tip.
[0025]
The drive coupler 15 has a cylindrical shape, and an internal thread for screwing a short self-piercing bolt 22 provided at an end of the long FRP hollow tube 14 and a self-piercing bolt 13 previously placed on the inner peripheral surface thereof. 26, 27, a spline protrusion 25 that is long in the axial direction in front of the striking surface 24 provided in the middle of the outer peripheral surface, and a plurality of trim edges 28 at a drive coupler circumferential division angle substantially the same as the spline protrusion 25. A waterproof rubber ring 33 is attached to the end of the fitting surface with the drive sleeve 21.
[0026]
The trim edge 28 is a conventional cast steel so that the spline protrusion 25 and the striking surface 24 of the drive coupler 15 are not caught by the already drilled wall surface when the FRP hollow bolt 14 is pulled. It has the same acute angle as the edge of the made bit, and the edge is advanced while reaming the protruding part of the already drilled wall, and the slime generated by drilling the foremost lost bit 12 is independent. In this structure, it passes between the plurality of trim edges 28 and is discharged rearward.
[0027]
The inside of the drive sleeve 21 is a fitting portion 29 to the drive coupler 15, and a concave groove 30 is formed on the inner peripheral surface of the drive sleeve 21 to externally fit the spline protrusion 25 and transmit rotation, and the tip surface is a striking surface. 24 ′, and the inside on the rear end side is a screw hole 31 into which the long driving rod 20 is screwed.
[0028]
【The invention's effect】
As described above, by implementing the injection-type fore-polling work according to the method of the present invention, the work, which has been conventionally carried out during the steel support works installed at intervals of about 1 m, is carried out every two or more times. The injection fore-polling process can be greatly reduced from the cycle time, so that the construction speed is significantly improved and great economic efficiency can be obtained.
[0029]
In addition, by adopting the drive coupler system of the present invention, the FRP hollow bolt used as the subsequent pipe of the self-drilling bolt can be steadily inserted into the preceding ground without being damaged, and the FRP bolt can be pressed into the solidified material. Since it can be excised with a general-purpose excavator during subsequent excavation, the FRP hollow bolt will not affect the shape of the steel support that will be installed subsequently, and the same support can be used, making work management complicated. Opened.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing an embodiment of an injection type forepoling according to the present invention. FIG. 2 is a vertical side view showing a caulking state of a natural ground outlet portion of an FRP hollow bolt terminal. FIG. 4A is a vertical side view of a drive sleeve used in the present invention, and FIG. 5B is a front view of the drive sleeve used in the present invention. FIG. 5A is a side view of a drive coupler used in the present invention. Figure, (B) is a longitudinal side view of the same, (C) is a front view of the same. [FIG. 6] A vertical side view showing the state of implementation of a conventional injection type forepoling [FIG.
DESCRIPTION OF SYMBOLS 1 Steel support 2 Hollow steel pipe 11 Solidification material discharge port 12 Lost bit 13 Self-drilling bolt 14 FRP hollow bolt 15 Drive coupler 16 Tunnel jumbo 17 Guide cell 18 Rock drill 19 Driving sleeve 20 Driving rod 21 Drive sleeves 22 and 23 Perforated bolts 24, 24 'Strike surface 25 Spline protrusions 26, 27 Female thread 28 Trim edge 29 Fitting portion 30 Groove 31 Drive sleeve screw hole 32 Caulking material 33 Water-stop rubber ring

Claims (3)

A drilling machine with a hollow structure with a lost bit at the tip and a self-drilling bolt with a continuous thread on the outer periphery, and then connecting the FRP hollow bolt with a drive coupler that allows subsequent placement. The FRP hollow bolt is installed in the inner hole of the long driving rod attached to the drive rod, and this drive coupler is rotated and hit directly by the drive sleeve attached to the tip of the driving rod, and the subsequent FRP hollow bolt is grounded. After drilling so as to pull to the mountain, after pulling out the driving rod and drive sleeve, caulk the outlet part from the ground of the FRP hollow bolt, inject the solidified material from the end of the subsequent FRP hollow bolt, It is discharged from the lost bit hole and pressed into a natural ground, and a solid ground consolidation method using self-drilling bolts and FRP bolts. Implementation of the natural ground consolidation method in the direction of tunnel excavation, every two or three steel supporters of the same shape, while excavating the tunnel while cutting the subsequent FRP hollow bolt part The preceding ground consolidation method using the self-drilling bolt and the FRP bolt according to claim 1. The drive coupler used in the natural ground consolidation method is formed so as to connect the self-drilling bolt and the FRP hollow bolt, and the drive coupler is directly hit and rotated from the drive sleeve provided at the tip of the driving rod. When a striking surface that can be transmitted, a plurality of spline protrusions, and a subsequent FRP hollow bolt are placed, the protrusions do not collide with the hole wall that has been previously excavated, and subsequent drilling is not difficult. From the lost bit in the front, the subsequent drilling operation can be carried out while re-reaming the hole wall of the already drilled hole in front of the striking surface and the spline protrusion, in order to prevent the passage of the waste soil. A drive coupler used in a preceding ground consolidation method in which trimming edges having a slightly smaller diameter and multiple circumferential directions are provided.

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